The invention relates to solid-state devices, and more particularly to melt-grown solid-state devices having unique structures and/or operating characteristics.
These solid-state devices include semiconductor, photoelectric, electroluminescent, laser, and many other optoelectromagnetic devices.
For simplicity, the invention is described mostly in connection with a semiconductor device having a signal-translating or modulating barrier region that comprises a pn junction. It is to be noted that other types of barrier regions, including those comprising Schottky barriers interfacial rectifying barriers, metal-oxide junctions, or in general, any regions capable of active electronic signal translation or modulation, by means of controlled flow and interaction therein of electronic carriers in the form of electrons and holes, of input optoelectromagnetic signal of a prescribed kind into the desired, translated or modulated, output signal. Active signal translation is typified by the action of semiconducting diodes and transistors, in sharp contrast to those of such passive components as resistors, capacitors, and inductances.
The semiconductor diode, for example, comprises the well-known pn junction that is capable of selectively and alternately allowing and substantially blocking the flow of electronic signal current carriers in accordance with the type of the signal applied thereto for translation. Specifically and as an example, electronic current flow easily under forward bias, but is substantially blocked under reverse bias, the conductance differing by over 10.sup.3 times in the two states.
The material or materials making up the barrier region will be hereinafter called (solid-state) device materials. These include not only semiconductor, photoelectric, thermoelectric, electroluminescent, . . . substances; but also dopants; carriers life-time controllers; carriers flow path controllers; and eutectic or dendriticforming or modifying substances for eutectic, cellular, granular, or dendritic devices. In addition, these device materials also include such substances as those that improve the characteristics of the barrier region in operation or during manufacture. For example, substances that enhance selective diffusion, oxidation, etching, or shaping of the barrier region are also considered as "device materials." On the other hand, the device materials do not include the substances for resistors, capacitors, inductances, and contacts, which are not an essential part of the signal-translating barrier region.
Existing solid-state device requires fairly complicated and expensive processing procedures to manufacture. The first step in a typical device manufacture is to grow a single crystal from a seed, by the Czochralski method as described by, for example, Clarke and Tomono in their U.S. Pat. (Nos. 2,778,198 and 3,192,082). Both ends of the resultant crystal are discarded and only the central portion of the crystal is sliced into thin wafers, which are then carefully ground and polished. Next come such critical steps as cleaning, diffusion, oxidation, rediffusion, plating, chemical etching, and metallization, . . . , with numerous tests sandwiched in between. The finished wafer, if good, is then diced into chips to be mounted, contacted, and canned. It is no wonder that the yield is often low, not infrequently zero in cases of large-scale, integrated circuitries.
In addition, the existing devices, even in integrated circuits, are relatively bulky and heavy, and consume much power to operate. Further, they are often slow in responses because of their large sizes; expensive in costs; and unreliable in operations.